The matamata turtle's name is Spanish for 'I kill I kill'—a fitting name for a skilled hunter. Matamatas will sit on the bottom of a river and wait for fish or aquatic invertebrates to swim close and then they will quickly open their mouths wide, sucking in both water and prey. The turtles eject the water and swallow their food.

Because of the shape of the matamata turtle's shell, it can be camouflaged as it sits in the water and waits for its prey. The shell has several large knob-like protrusions, and will likely be covered with a layer of algae.

The matamata's head and the neck are big and flat, with many warts and ridges. Its snout is very long, which enables the turtle to breathe while being almost completely submerged.

While these turtles prefer to spend a majority of their time underwater, they are not very good swimmers. Instead, matamatas walk along the bottom of the pond or river, extending their neck and snout up to the surface whenever they need to grab a breath of air.

Matamata turtles reach sexual maturity at about age five, at which point the females may begin laying clutches of eggs on high ground near a river or creek. The clutches generally contain between 12 and 28 eggs, which will be incubated for about 208 days. Mothers do not care for their hatchlings, leaving the young to fend for themselves and find their own food.